Sewing machine



C. F. WHKTAKER SEWING MACHINE Filad May l0, 1959 Patented dune 25, Wd@

@IEWHNG MACHINE @ari iF. Whitaker, itieveriy, Mass.,

assigner to United Shoe Machinery Corporation, Borough orlli'iernington, .Hersey N. il., a corporation ci New Application ltliaylill, i939, Serial No. 272,771

0 Ciainis.

The present invention relates to sewing machines, more particularly shoesewing machines, and is concerned with improvements in thread handlingand supply mechanisms therefor.

In U. S. Letters Patent No. 1,909,157, issued May 16, 1933 to Erastus E.Winkley, there is disclosed novel and improved means for providing asewing machine with thread from a rotatably supported spool or similarWound'mass, enabling the thread to be drawn off radially withoutvariations in thread tension due to jerking and overrunning of the mass.This is accomplished, according to the patent, by providing a yieldingarm for holding aside a bend of thread between the rotatably supportedthread mass and the stitchforming devices, the arm yielding under a pullexerted on the thread to give up thread from the bend while the massaccelerates. When the tension on the thread relaxes, the arm, returningunder the action of a spring to reestablish a bend in the thread, iscaused to apply a brake to retard the rotation of the thread spool andprevent overrunning thereof.

While the arrangement of the prior patent has proven highly effective insupplying thread without variations in tension to the stitch-formingdevices of a sewing machine during the operation thereof, certaindifficulties have arisen by reason of the fact that the friction brakecontrolled by the yielding arm and tending to resist rotation of thethread mass prevents the thread from being drawn 01T as freely asdesired when the machine is stopped. This diculty is particularlyencountered when the devices of the patent are employed with machineswhich sew a chainstitch seam since it is necessary in such machines thatthread be given up as freely as possible when the machine is stopped topermit removal of the work without pulling out the seam just sewn.

It is accordingly the object of the present invention to provide noveland improved means for providing a sewing machine with thread from arotatably supported wound mass, enabling the thread to be drawn oifradially during the operation of the machine without jerking oroverrunning of the mass, and arranged, upon stopping the machine to giveup thread to permit removal of the work with the least possibleresistance to the free withdrawal of the thread from the machine.

To this end, the present invention involves the combination with asewing machine having stitch-forming devices and control means forstarting and stopping the machine, oi' means for the looper at 8, thethread (ci. ira-ss;

rotatably supporting a wound mass of thread employed by thestitch-forming devices, a yielding arm for holding aside a bend ofthread between the thread mass and the stitch-forming devices, and meansactuated by the control stopping the machine to cause the arm to give upthread from the bend. The yielding arm, as in the patent above referredto, is arranged to control the application of a friction brake tendingto resist rotation of the thread mass, and in the H0 embodiment of theinvention hereinafter described, the arm is caused to give up threadfrom the bend upon stoppingA the machine without releasing the brake.When the machine is again started, the arm is actuated to reestabuconstruction and arrangement to the machine 25 shown and described inPatent No. 1,108,560 issued August 25, 1914 to Andrew Eppler, themachine having mounted thereon the devices of the invention forsupporting and controlling the thread mass; and Figure 2 is a rearelevation of 30 said supporting and controlling devices alone.

In the shoe sewing machine illustrated in Figure 1, the curved hookneedle is indicated at 6, arm at i0, and the back rest or bunter at l2,these as other instrumentalities not illustrated, being similar to thoseof the machine Vof Patent No. 1,108,560 above referred to. The machineis provided with the usual starting and stopping mechanism, controlledby foot treadle through treadle rod I6. As in the aforesaid patent No.1,108,560, the starting and stopping mechanism is arranged to releasethe thread tension upon stopping the machine by relieving the pressureof brake shoe i8 on brake disk 20 45 on the tension wheel shaft 2l.

The thread supply, instead of consisting of a cop or package from whichthe thread is drawn of endwise, employs radial delivery of the threadfrom a rotatably supported wound mass, avoiding any tendency of thethread to kink and thus interfere with its free passage through themachine. The supporting mechanism for the thread mass is similar exceptas hereinafter described,` to that 55 means upon invention,

parts, as well .35

I 4 acting 4o illustrated and described in the patent to Winkley No.1,909,157 hereinbefore referred to.

The thread mass, which may be a Wound spool or the like, is indicated at22. and is fixed upon a hub 24 provided at one end with a brake disc 26and rotatably mounted by means of ball bearings 28 on the spindle 30.The spindle is received within a bore in one end of a bracket 32, thebracket having a base 34 by which the thread supporting mechanism isattached at a suitable point to the machine, in the illustrativeembodiment, the bracket being mounted at the top of the machine.

Secured to the spindle 30 between the bracket 32 and the brake disc 26on hub 24 is a radially extending member 36 having secured in its outer'end a stud 38 in parallel relation to the spindle.

A sleeve 40 is rotatably mounted on the spindle, the sleeve having atone end a radially extending a 42 provided with friction material 44adapted to engage the periphery of brake disc 26 of the threadsupporting hub 24. The other end of the sleeve is provided with a bo-ss46 grooved to receive the two legs of a loop of wire 48, a cap piece 50and bolt 52 clamping the wire to the boss. A coil spring 54 yieldinglyurges the sleeve in a direction to maintain the friction brake inengagement with the brake disc 26, and to hold aside in the loop at theouter end of the wire 48 a bend in the thread between the 'supply spool22 and the wax pot 56.

As in the arrangement of the Winkley patent, upon a quick pull on thethread by the sewing instrumentalities, the arm 48 dips to give upthread from the bend, delaying the eiect of the pull on the rotatablymounted spool and thus avoiding possible breakage, until the mass hasVhad time to accelerate free of the effect of the brake. As the pulldecreases, the arm is raised by the spring 54 to reestablish the bend inthe thread and at the same time to cause the application of the frictionbrake to check the rotation of the thread mass and prevent overrunning.

Although the above described arrangement does not result in anysubstantial increase in the thread tension during the operation of themachine, nevertheless the additional tension on the thread, when thearrangement is employed in chain stitch machines, as-compared with thesubstantially tensionless withdrawal of thread endwise from a cop, hasbeen found objectionable when the work is to be removed from the machineupon stopping. In order to allow the thread to be drawn through themachine with the least possible resistance upon removing the work, as isnecessary in machines of the type described which sew a chainstitchseam, the

thread supporting and controlling mechanism is arranged to makeavailable a length of thread upon stopping the machine suicient topermit the Work to be removed without drawing oi thread from the woundmass.

To this end, the spindle 36, instead of being xedly mounted on themachine asin the patent toWinkley, is rotatably received within the borein supporting bracket 32. The spindle projects beyond the bracket asshown in Figure 2, and has secured to its projecting end a short radialarm 58, a stud clamping the split end of the arm to secure the same onthe spindle.

The arm 58 is rocked upon stopping and starting the machine by treadleactuated connections comprising a rod 62 pivotally connected at itsupper end to the outer end of arm 58 and at its lower end to the treadlerod I6. 'Ihe rod 62 is provided with a rearwardly and sidewardly offsetportion 64 to compensate for the lack of vertical alignment of the arm62 with the treadle rod, and also to permit the rod to clear themachine. 'I'he connection 66 between the rod 62 and the treadle rod i6is in the nature of an orf-set coupling, being clamped at one end to theupper portion of the treadle rod and provided at its other end with agenerally vertical bore through which the rod 62 passes. Upper and lowerstop collars 68 and 'I8 permit adjustment of the rod 62 heightwise ofthe treadle rod. while permitting a certain degree of looseness of theparts to prevent the rod 62 from causing the treadle rod to bind.

While the machine is in operation, with the treadle in depressedposition, the spindle is maintained at the limit of its rocking movementin clockwise direction, with the member 36 and the yielding arm 48substantially in the position shown in full line in Figure l. The arm,dipping under an increased pull on the thread and rising again as thepull decreases, holds aside a bend of thread while' maintainingsubstantially uniform tension therein.

Upon stopping the machine, the treadle is permitted to rise, rocking thespindle in counterclockwise direction to move the member 36 and the arm48 mounted thereon to the position indicated in dot-and-dash line. Sincethe member 36 is mounted to rotate about a center concentric with'thehub 24, i. e., both member and hub are mounted on the spindle 30, nomovement of the arm 48 on its pivot 38 and relative to the member takesplace as the latter is rocked, and hence the friction brake 42 is notreleased, the hub 24 rotating as a unit with the spindle 30 and member36. The arm 48, having been moved bodily to the position shown by thedot-and dash line gives up thread from the bend to provide a slack loop,indicated generally at 12, adjacent the wax pot 56. The parts, and moreparticularly the radial arm 58, are preferably so proportionedrelatively to the throw of the treadle rod I6 that the amount of slackthread given up from the bend is sufiicient to permit the work to bewithdrawn from the machine a convenient distance before cutting thethread, without requiring additional thread to be drawn off from thewound mass 22.

When the treadle is depressed by the operator to start the machine inoperation, the spindle 36 is rocked to move the member 36 to itsclockwise position, thus urging the arm 48 upwardly, under the action ofcoil spring 54, to re-establish the bend in the thread. The arm, inmoving to operating position, first takes up whatever slack thread wasnot pulled from the machine when the Work was removed at the end of theprevious sewing operation. thread to make up for that previouslywithdrawn with the work is pulled off from the supply, the pull on thethread causing the arm 48 to release the friction brake arm 42 andpermit the wound mass to rotate to give up whatever thread is needed forthe reestablishment of the bend.

While the invention has been illustrated and described as embodied in aparticular type of sewing machine, it is evident that the invention maybe employed to advantage in sewing machines of other types andarrangements where it is desirable that the thread be supplied radiallyfrom a Wound mass under uniform tension Thereafter, any additionaly andwithout overrunning of the mass, while permitting the work to be removedwhen the machine is stopped without hindering to the slightest degreethe free withdrawal of the thread.

Having thus described the invention, in its preferred form, and anembodiment thereof having been illustrated, what is claimed is:

1. A sewing machine having, in combination, stitch-forming devices,control means for starting and stopping the machine, means forrotatablyl supporting a wound mass of thread employed by thestitch-forming devices, a yielding arm for holding aside a bend ofthread between :the thread mass and the stitch-forming devices, andmeans actuated by the control means upon stopping the machine to causethe yielding arm to give up thread from the bend.

2. A sewing machine having, in combination, stitch-forming devices,control means for starting and stopping the machine, means for rotatablysupporting a wound mass of thread employed by the stitch-formingdevices, a yielding arm for holding aside a bend of thread between thethread mass and the stitch-forming devices, frictional braking meanscontrolled by the yielding arm for resisting rotation of the threadmass, and means actuated by the control means upon stopping the machineto cause the yielding arm to give up thread from the bend.

3. A sewing machine having, in combination, stitch-forming devices,control means for starting and stopping the machine, means for rotatablysupporting a wound mass of thread employed by the stitch-formingdevices, a yielding arm for holding aside a bend of thread between thethread mass and the stitch-forming devices, frictional braking meanscontrolled by the yielding arm for resisting rotation of the threadmass, and means actuated by the control means upon stopping the machineto cause the yielding arm to give up thread from the bend whilemaintaining the frictional braking means eiective to resist rotation ofthe thread mass.

4. A sewing machine having, in combination, stitch-forming devices,control means for start= ing and stopping the machine, means forrotatably supporting a wound mass of thread employed by thestitch-forming devices, a yielding arm for holding aside a bend ofthread between the thread mass and the stitch-forming devices, and meansactuated by the control means upon stopping the machine tc cause the armto give up thread from the bend, and upon starting the machine to causethe arm to reestablish the bend in the thread.

5. A sewing machine having, in combination, stitch-forming devices,control means for starting and stopping the machine, means for rotatablysupporting a wound mass of thread employed by the stitch-forming devicescomprising a hub upon which the wound mass is fixed and a spindle onwhich said hub is rotatably mounted, an arm carried by the spindle forholding aside a bend 4oi. thread between the thread mass and thestitchforming devices, and means actuated by the control means uponstopping the machine to rock the spindle to cause the arm to give upthread from the bend.

6. A sewing machine having, in combination, stitch-forming devices,control means including a treadle for starting and stopping the machine,means for rotatably supporting a wound mass of thread employed by thestitch-forming devices comprising a hub upon which the Wound mass is xedand a spindle on which the hub is rotatably mounted, a yielding armcarried by the spindle for holding aside a bend of thread between thethread mass and the stitch-forming devices, frictional braking meanscontrolled by the yielding arm for resisting rotation of the hubrelative to the spindle, and treadle operated connections for rockingthe spindle upon stopping the machine to move the yielding arm bodily tocause thread to be given up from the bend while maintaining thefrictional braking means eective to resist rotation of the thread mass.

'7. .A sewing machine having, in combination, stitch-forming devices,control means for starting and stopping the machine, means for rotatablysupporting a wound mass of thread employed by the stitch-forming devicescomprising a hub on which the wound mass is fixed and a spindle on whichthe hub is rotatably mounted. a member secured to the spindle, an armpivotally mounted on said member, the arm being adapted yieldingly tohold aside a bend of thread between the thread mass and thestitch-forming devices, frictional braking means carried by the memberand controlled by the arm for resisting rqtation of the hub relative tothe spindle, and means actuated by the control means upon stopping themachine to rock the spindle and thereby to move the arm bodily to causethread to be given up from the bend while maintaining the frictionalbraking means effective to resist rotation of the thread mass.

8. A sewing machine having, in combination, stitch-forming devices,control means including a treadle for starting and stopping the machine,means for rotatably supporting a wound mass of thread employed by thestitch-forming devices comprising a hub on which the wound mass is xedand a spindle on which the hub is rotatably mounted, a member mountedconcentrically with the spindle, an arm pivotally mounted on the memberand adapted yieldingly to hold aside a bend of thread between the threadmass and the stitch-forming devices, frictional braking means controlledby the yielding arm for resisting rotation of the hub relative to themember, and means actuated by the treadle upon stopping the machine forrocking the member in a direction to i cause the arm to give up threadfrom the bend while maintaining the frictional braking means effectiveto resist rotation of the thread mass, and upon starting the machine torock the member in the opposite direction to cause the arm toreestablish the bend in the thread.

CARL F. WHITAKER.

